Anesthesia-Strauss

Question 1

methods of administration for inhalationals

Answer 1

• nasal hood for oral procedures
• full face mask for short procedures outside face
• LMA (laryngeal mask anesthetic) for longer procedures
• endotracheal inbubations for longer procedures (goes between vocal cords)

Question 2

what is MAC?

Answer 2

minimum alveolar concentration

-concentration of an anesthetic at which 50% of patients will not respond to a noxious stimulus

Question 3

How much ‘MAC’ is given for induction vs maintenance?

Answer 3

-induction 2-3 MAC and maintenance usually 0.5-1.5 MAC

Question 4

what are the stages of anesthesia?

Answer 4

Guedel’s stages (based on ether)

• stage I Analgesia
• II excitement
• III surgical Anesthesia (surgery here)
• IV Apnea (can die here)

Question 5

blood gas solubility

Answer 5

• this coefficient represents the ability of an agent to dissolve in blood
• only drugs NOT dissolved can see the brain, so the lower the BGS the faster the rise in arterial gas tension
• also shows speed of recovery

Question 6

examples of some of the minor inhalational agents

Answer 6

• ethyl chloride
• chloroform
• diethyl ether
• methoxyflurane
• nitrous oxide (not potent, but hardly minor)

Question 7

what inhalational agent shows liver toxicity?

Answer 7

halothane

Question 8

which inhalational agent has some seizure activity?

Answer 8

enflurane

Question 9

which agent has the lowest blood gas solubility?

Answer 9

Desflurance

-BGS 0.42

Question 10

pungent odor, so not well tolerated by airway for indution-breath holding, coughing and laryngospasm

Answer 10

Desflurane

Question 11

desflurance

Answer 11

-Requires special vaporizer (expensive)
-Lowest B/G solubility of all (0.42) so
very fast in and out
-Pungent odor so not well tolerated by airway for induction-breath holding, coughing and laryngospasm
-High MAC of 6%
-Causes tachycardia so no change in
cardiac output
-Fast shallow breathing with inc PaCO2
-greenhouse gas

Question 12

Isoflurane

Answer 12

-Introduced in 1981
-MAC is 1.2%
-Moderately low BGS so relatively fast in and out
-Pungent ether-like odor so no induction
-Minimal cardiac depression via inc in
HR of 10% (less than Des)
-Good bronchodilator
-Slight metabolism in liver but small (0.17%)
-Good muscle relaxation

Question 13

which agent is a good bronchodilator

Answer 13

isoflurane

Question 14

• Newest agent now!
• Very low BGS (near N2O)
• Very little irritation so can breathe the patient down
• MAC 1.71%
• Great in OMS outpt anesthesia by itself
• Mild negative inotrope and no tachycardia. CO drops slightly more than others
• VT drops and rate slightly
• 5% metabolism but not toxic
• Must have high flow to prevent Compound A toxicity

Answer 14

Sevoflurane

-“the workhorse”

Question 15

properties of narcotics (IV)

Answer 15

• all are analgesic
• varying effect on other receptors
• all are addicting and induce tolerance
• main effect is reaction to pain
• lesser effect on perception of pain
• all are respiratory depressants
• all cause some nausea
• all are constipating
• relief is better with severe, sharp pain rather than constant dull pain

Question 16

divisions of narcotics

Answer 16

• opiates: morphine, codeine
• synthetic opiates: dilaudid, heroin
• opiods (synthetic compounds): fentanyl, demerol, alphaprodine

Question 17

patient has pin point pupils, what is that called and what are they probably on?

Answer 17

-meiosis (opposite would be midriasis), and meiosis is a mallmark of morphine

Question 18

what narcotic is good for MI patients?

Answer 18

morphine

Question 19

example of synthetic opiod

Answer 19

demerol, fentanyl (sublimaze)

Question 20

demerol

Answer 20

• makes the patient have a sympathetic response (I think)
• shows anticholinergic effects
• duration 3-4 hr IM, 30-60 min IV
• good for postop analgesic but fair for sedation, OPD GA

Question 21

synthetic opiod that is used a lot

• it’s a potent narcotic: 100X morphine
• fast onset (3 min), short duration (15-30 min IV); good for OPD

Answer 21

fentanyl (sublimaze)

Question 22

“stiff chest syndrome”

-what is it, and what causes it?

Answer 22

caused when over 100 mcg of fentanyl (sublimaze) is given. It doesn’t happen to everyone, but their chest becomes rigid and you can’t even ventilate them

Question 23

• sedative-hypnotics
• relaxation and reduction of anxiety
• act on limbic system and lesser extent on RAS
• increase GABA levels locally in these systems

Answer 23

Benzodiazepines (given IV)

Question 24

examples of benzodiazaepines and their duration of action

Answer 24

• Long acting (20-80 hours): diazepam (valium)
• medium acting (10-20 hrs): lorazepam
• short acting (2-5 hrs): midazolam (versed) and triazolam (halcion)

Question 25

Benzodiazepines

Answer 25

- effect on limbic, RAS (renin-angiotensin system) - sedative, hypnotics - powerful anxiolytic - generally good anticonvulsants - all are cardiac and ventilatory depressants - good muscle relaxants - all lead to dependence, tolerance - can see paradoxical (opposite of expected) reactions

Question 26

Valium vs Versed | Diazepam vs Midazolam

Answer 26

Versed is about twice as strong (potent) as Valium, but has a smaller therapeutic index so it's more dangerous Versed more: potent, anterograde amnesia, resp depression Valium more: injection pain,/ vein inflammation (thrombo?) and longer duration

Question 27

active metabolites of benzodiazepines

Answer 27

- I think these are specifically referring to valium and versed - oxazepam-Serax - desmethydiazepam - apha 1-hydroxymidazolam

Question 28

what is the principal mechanism of barbiturates?

Answer 28

re-distribution

Question 29

three categories of barbiturates

Answer 29

- ultra-short acting (thio, metho) - short acting (nembutal, seconal) - long acting (amytal, phenobarbital)

Question 30

what drugs discussed are metabolized by the liver and to what extent?

Answer 30

-Barbiturates: 20%/hr

Question 31

which drug is an anti-analgesic at low doses?

Answer 31

barbiturates | -they actually make the pain worse at low dose

Question 32

patient has Acute intermittent porphyria...

Answer 32

don't give them barbiturates

Question 33

contraindications for barbiturates

Answer 33

- allergic | - acute intermittent porphyria

Question 34

site of action of barbiturates

Answer 34

Reticular activating system (RAS)

Question 35

thiopental (Pentothal)

Answer 35

- a barbiturate - main use is as induction agent in GA (3-4 mg/kg) - may see severe histamine release - sedation dose: 20-50 mg total

Question 36

truth serum

Answer 36

thiopental in sedation dose (20-50 mg)

Question 37

examples of barbiturates

Answer 37

- thiopental (Pentothal) | - methohexital (Brevital)

Question 38

- most common agent on OMFS due to short onset and quick duration of action - 3X more potent than pentothal (thiopental) - induction dose=1 mg/kg - may cause shakes - intermittent injection technique

Answer 38

methohexital (Brevital) | -Brevital shakes

Question 39

Brevital respiratory and cardiac effects

Answer 39

``` Respiratory -dose-dependant depression -hiccups common -can obtund laryngeal/pharyngeal reflexes -increased rate-decreased tidal vol Cardiac -increased HR -decreased PVR and BP ```

Question 40

similar to brevital, but non-barbiturate inducing agent - white milky, viscous material - injection burns-lidocaine

Answer 40

Propofol (Diprivan) | -used instead of barbiturates

Question 41

induction agent - phencyclidine derivative (non-narcotic, non-barb, rapid acting) - profound analgesia - patient doesn't appear asleep - DVS-inc HR and BP

Answer 41

Ketamine | -"special K"

Question 42

when is ketamine contra indicated?

Answer 42

epilepsy or hypertension

Question 43

what drugs are the anticholinergics?

Answer 43

- Atropine | - Robinul (glycopyrrolate)

Question 44

vagolytic effect on heart rate and secretions | -used in OMFS for secretions and in kids for HR

Answer 44

atropine

Question 45

-drying/HR ratio increased

Answer 45

Robinul (glycopyrrolate)